Whenever a compressible fluid such as gas is introduced within an incompressible fluid such as liquid gas bubbles are formed.
Gas bubble forming devices can be used in various ways for different applications and typically function via the introduction of a continuous flow of gas directed into; 1) a vertical column having an open upper end and most often an open bottom end, these are typically termed as a static tube aerator; 2) a distribution manifold or diffuser comprising of orifices; 3) a venturi type fixture that functions with a continuous flow of pressurized liquid moving through a restriction generating a slight vacuum that can draw gas into the liquid thereby forming gas bubbles to be entrained within the liquid and released into the bulk liquid.
The gas bubbles once released into the liquid will change the density of the liquid within the area of discharge and thereby provide a means for generating a flow and or mixing the liquid as is the case of a static tube type process. In addition gas can be distributed via a diffuser or a venturi fixture for transferring gas such as oxygen into the liquid as well as for mixing the liquid and its contents.
Prior art devices that operate with a continuous flow of gas for the purpose of pumping liquid via an ‘airlift’ process are inefficient since they have a small lift capacity and suction or flow velocity as compared to mechanical pumping devices. Therefore, their use is limited to pumping liquid only vertically a short height above the liquid surface level. The limited suction or flow velocity can further lead to clogging problems, when continuous gas flow ‘airlift’ type pumps are applied within liquid containing particulates or sludge.
Improvements with respect to the continuous gas flow ‘airlift’ process employed for the purpose of pumping liquid and most specifically transferring a liquid out from a body of liquid have recently been introduced.
U.S. Pat. No. 6,162,020 by Masao Kondo discloses an airlift pump apparatus and method that injects air intermittently into a vertical riser.
U.S. Pat. No. 8,047,808 by Masao Kondo discloses a ‘geyser pump’ for vertically moving a liquid upward.
The intermittent fluid pump of the current invention provides several improvements over prior art intermittent ‘airlift’ and ‘geyser’ pumps. Additionally disadvantages apparent with prior art continuous flow gas bubble forming devices currently employed for mixing and distributing liquid can be overcome with the use of the intermittent fluid pump, which can provide greater energy value, application adaptability and reduced maintenance requirements.